What caused our pink, yellow, and two-toned roses to turn red? —Theresa Beard, Talladega, AL
If your rose bushes bloomed pink or yellow or were two-toned the first year, but bloomed red in years after that, you’re probably left with canes that grew from the rootstock—underground portions below the graft union. You’ve lost the “desirable” named cultivars that form the upper part of the plants. This can happen when roses are inadequately protected in winter (when temperatures drop to about 20ºF, canes are sometimes permanently damaged or killed), or when something else damages the grafted tops so severely that they die. They’re then replaced by canes from the hardier, underground rootstock.
Unless you’re happy with the red flowers (chances are they’re far smaller and less showy than the originals), dig out the roses and replace them. Plant new roses with the graft union slightly below the soil surface, and give the above-ground portion adequate protection over winter. Or buy only “own-root” roses—those that are not grafted to a different rootstock.